Evaluation of the implantation of transpedicular screws in spinal instrumentation with free-hand technique and navigation-assisted with intraoperative computed tomography: An analytical-positional study / Evaluación de la implantación de tornillos transpediculares en instrumentación espinal con técnica free-hand y navegación asistida con tomografía computarizada intraoperatoria: un estudio analítico-posicional

Spinal instrumentation using transpedicular screws has been used for decades to stabilize the spine. In October 2018, an intraoperative CT system was acquired in the Neurosurgery service of the University Hospital Complex of Vigo, this being the first model of these characteristics in the Spanish Public Health System, so we began a study from January 2015 to December 2019 to assess the precision of the transpedicular screws implanted with this system compared with a control group performed with the classical technique and final fluoroscopic control. Methods: The study was carried out in patients who required transpedicular instrumentation surgery, in total 655 screws were placed, 339 using the free-hand technique (Group A) and 316 assisted with intraoperative CT navigation (Group B) (p>0.05). Demographic characteristics, related to surgery and the screw implantation grades were assessed using the Gertzbein–Robbins classification. Results: 92 patients were evaluated, between 12 and 86 years (average: 57.1 years). 161 thoracic screws (24.6%) and 494 lumbo-sacral screws (75.4%) were implanted. Of the thoracic screws, 33 produced a pedicle rupture. For the lumbo-sacral screws, 71 have had pedicle violation. The overall correct positioning rate for the free-hand group was 72.6% and for the CT group it was 96.5% (p<0.05). Conclusion: The accuracy rate is higher in thoracic-lumbar instrumentation in the navigation group versus free-hand group with fluoroscopic control (AU)

La instrumentación espinal con tornillos transpediculares se ha utilizado durante décadas para estabilizar la columna. En octubre de 2018 se adquirió un sistema de TC intraoperatoria en el Servicio de Neurocirugía del Complejo Hospitalario Universitario de Vigo, siendo este, el primer modelo de estas características en el Sistema Público de Salud español, por lo que iniciamos un estudio desde enero de 2015 a diciembre de 2019 para evaluar la precisión de los tornillos transpediculares implantado con este sistema frente a un grupo control realizado con la técnica clásica y control fluoroscópico final. Métodos: Se realizó un estudio con pacientes que requirieron cirugía de instrumentación transpedicular, en total se colocaron 655 tornillos, 339 con la técnica free-hand (grupo A) y 316 asistidos con navegación por TC intraoperatoria (grupo B) (p>0,05). Se evaluaron las características demográficas relacionadas con la cirugía y los grados de implantación de tornillos según la clasificación de Gertzbein-Robbins. Resultados: Se evaluaron 92 pacientes, entre 12 y 86 años (promedio: 57,1 años). Se implantaron 161 tornillos torácicos (24,6%) y 494 tornillos lumbosacros (75,4%). De los tornillos torácicos, 33 produjeron una rotura pedicular. En el caso de los tornillos lumbosacros, 71 tuvieron violación pedicular. La tasa de correcto posicionamiento en general para el grupo free-hand fue del 72,6% y para el grupo de TC fue del 96,5% (p<0,05). Conclusión: La tasa de precisión es mayor en la instrumentación torácica-lumbar en el grupo de navegación que en el grupo de manos libres con control fluoroscópico (AU)

Brainstem and Autonomic Nervous System Dysfunction: A Neurosurgical Point of View.

Central autonomic control nuclei and pathways are mainly integrated within the brainstem, especially in the medulla oblongata. Lesions within these structures can lead to central dysautonomia.Central autonomic control structures can be damaged by tumors, during surgery, or by other neurosurgical pathologies. These may elicit clinical or subclinical autonomic complications that can constitute a serious clinical problem.The authors present a broad review of the central autonomic nervous system, its possible dysfunctions, and the relation between neurosurgery and this "not-well-known system". Preliminary results of an autonomic study of brainstem lesions that is currently being carried out by the authors are also shown.

Autonomic dysfunction elicited by a medulla oblongata injury after fourth ventricle tumor surgery in a pediatric patient.

We report the case of a 9-year-old male patient with a recurrent fourth ventricle anaplastic ependymoma who developed severe arterial hypertension and blood pressure lability during and after surgery. A punctual bilateral lesion located within mid dorsal medulla oblongata caused by both infiltration and surgical resection was observed in postoperative MRI. Three years later, the patient remained neurologically stable but the family referred the presence of a chronic tachycardia as well as palpitations and sweating with flushing episodes related to environmental stress. On autonomic evaluation, an increase in sympathetic outflow with tachycardia together with orthostatic hypotension caused by baroreceptor reflex dysfunction was observed. We postulate that a bilateral injury to both nuclei of the solitary tract may have caused central dysautonomia.